The present invention relates to a reactor for conducting a continuous multi-phase catalytic reaction and is particularly, though not exclusively, applicable to the catalytic conversion of syngas, produced by the reforming of methane, to hydrocarbon fuels, by a Fischer-Tropsch type of synthesis. Other reaction systems for which the apparatus would be suitable include various slurry reactions for the production of petrochemicals, the production of oxygenates from synthesis gas and dehydrogenation reactions. Additionally, however, the apparatus is equally useful in solid/liquid slurry treatment applications.